2010 Annual Report
1a.Objectives (from AD-416)
The current specific aims are: (1) profile the in vivo whole blood RNA and cytokine response to Salmonella Typhimurium (ST) infection in animals with high and low fecal shedding phenotypes; (2) using the same animals in Aim 1, profile the in vitro whole blood RNA and cytokine response to exposure to the general inflammatory endotoxin, lipopolysaccaride; (3) annotate response profiles for common expression patterns and functional themes and develop regulatory network information on response to inflammatory stimuli; and (4) test existing and develop improved predictive models for identifying pigs with decreased fecal shedding at multiple stages of post-infection pro and in naïve pigs.
1b.Approach (from AD-416)
Tests will be performed at BARC to quantitate RNA and protein levels for important markers of inflammatory and infectious processes critical to disease resistance. Simultaneously, the team plans to develop layers of information, based on transcriptional profiling data, on the mechanisms controlling inflammatory and infectious processes critical to disease resistance, and to integrate transcriptional and cromatin binding data available in the pig with similar data in other species to develop higher-level understanding of regulatory mechanisms.
Under this agreement samples have been collected for phenotyping pigs with superior immune responses to Salmonella infections, which would lead to safer pork products. ARS Researchers at Beltsville, MD, partnered with Iowa State University (ISU) and ARS Researchers at Ames, Iowa to review existing, and create new, RNA transcriptomic data on the immediate innate response to infection with the foodborne pathogen, Salmonella Typhimurium (ST). At ISU whole blood RNA and proliferative responses of ST infected pigs are being performed and results compared for pigs with high and low fecal shedding phenotypes (determined ARS Researchers at Ames, Iowa. ARS Researchers at Beltsville, MD planned tests to validate RNA and protein levels for important markers of inflammatory and infectious processes critical to disease resistance. Once collected response profiles will be annotated at ISU for common expression patterns, functional themes and inflammatory regulatory networks. This information will be used to develop a classification tool to predict and identify pigs with a low ST fecal shedding phenotype. The tool should be useful for pigs post-infection but would be best if naïve pigs with low shedding of bacterial pathogens could be identified. If such a predictor can be validated, using experimental and field populations (samples of which are available through this project), this approach can then be tested for heritability and utility in genetic improvement to potentially decrease Salmonella shedding and pork contamination.
Disseminating progress on this grant was through regular email and phone contact with the participating labs discussing project plans, experimental design and reviewing data and presentation options.